The present invention is directed to a fiber optic switch using MEMS (micro electro mechanical systems), and more specifically to a scalable nxc3x97n switch.
The great demand for data-centric services brought on by the explosive growth of Internet has led service providers to dramatically increase their capacity. All optical networks (AON) utilizing wave division multiplexing (WDM) is expected to satisfy the bandwidth requirements. As more networking is required at the optical layer, an all photonic switch is emerging as an enabling technology. While most switching in communication systems today is accomplished electronically, emerging AON will require switches to route signals purely in the optical realm to achieve higher bit rates. These network applications require switching matrices from 8xc3x978 to 1024xc3x971024.
Conventional optomechanical switches are mostly available in 1xc3x972 and 2xc3x972 configurations and rely on mature optical technologies. Large scale matrix switches are difficult to realize because of their complexity, size, and the number of moving mechanical parts requiring assembly.
Other attempts at silicon MEM switches are based upon torsional or hinged mirrors which are limited in angular excursion; and require angular sensors for feedback servo control to slew the mirrors into required angular positions. The difficulty in precise angular control and servo mechanisms which limits switching speed have prevented these analog techniques from realizing useful optical switching.
It is a general object of the present invention to provide a fiber optic switch which is scalable.
In accordance with the above object, there is provided an optical matrix switch having a plurality of cross-points for switching a plurality of information carrying light beams between any one of a plurality of input beams to any one of a plurality of output beams by choosing the appropriate cross-point of the matrix. Each cross-point is a micro electromechanical (MEM) type mirror having a first position where the mirror reflects the selected input beam to provide a selected one output beam and a second position where it provides a through path for transmission of said light beam. Means are provided for actuating a selected cross-point mirror to a first position to reflect the input beam to the output beam and for causing the remaining mirrors in the path of such beam to remain in the second position to allow through transmission.
In addition, a method is also provided of switching a selected one of a plurality of input optical signal paths to a selected one of a plurality of output optical signal paths comprising the steps of providing a matrix of optical mirrors at all cross-points of the input and output optical paths, selectively and digitally moving a mirror into an optical path to allow a selected input optical path to be reflected to a selected output optical path, and allowing the remaining mirrors in the optical path to provide through transmission.